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Linksys WET11: Bridge 30 Devices To Any Wi-Fi Network
eggboard writes "The Linksys WET11 lets you bridge a wired network with up to 30 devices to any wireless access point that uses Wi-Fi. The utility is enormous: you could build a pseudo-mesh network by pairing cheap Wi-Fi APs with this cheap ($129) Wi-Fi bridge. Before this, the only generic Wi-Fi bridge was proprietary: you'd buy a bridge from Alvarion that paired with one of their hubs, and spend several hundred each. Even the dual-WAP11 bridge approach of last year was wonky and required extra gear (although it can handle more devices than 30 since it's a protocol bridge, not a MAC bridge). I review the WET at O'Reilly's wireless developer's site."
I hang out at the WISP message board on broadbandreports.com ( http://www.dslreports.com/forum/dslalt ) and it seems that many WISPs are using these to connect customers to their wireless network. The WET11's antenna is detachable, so you can use an external one. It can also be configured to use POE (power over ethernet) by changing two jumpers.
0 109~roo t=dslalt~mode=flat
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There have been some cool mods like:
http://www.dslreports.com/forum/remark,422
http://www.dslreports.com/forum/remark,4123612~
By Walt Mossberg's substitute Nick Wingfield in his
Personal Technology column
Cool funny t-shirts for geeks, gamers and everyone else
I have been looking for a WiFi bridge to help a friend get cablemodem access: the cable company will not lay the cable to his house (cost > $1K), and it is about 300' from the road. One possibility I am considering is to use a pair of WiFi APs to bridge the gap. But they need to be rugged, to withstand temperatures from -30F to +100F, and rain/snow. None of the cheapo units comes in a weatherproof enclosure. Anyone know of any? I've looked around. Of course, the cost can't be more than $200 or so (each); the .com days are gone. :-(
It's a great little unit. Been playing around with it for about a month. It can use an external antenna (RP-SMA connector) also. It's also 70mW, which helps out on the transmissions.
r oo t=dslalt~mode=flat
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There are a few current threads about the WET-11 for Wireless ISPs here:
http://www.dslreports.com/forum/remark,4123612~
http://www.dslreports.com/forum/remark,3915738~
Dirk
I hope you view anonymous replies..
We've had a pair of Linksys WAP11 access points mounted in waterproof plastic electrical enclosures on top of our chiller towers at work for about 18 months. These chiller towers release slightly acidic moisture that coats everything. I the winter they don't run much so the access points are exposed to everything a michigan winter can dish out.
Open the phone book, find a local industrial electrical equipment supplier and pay them a visit. I think we paid around $30 ea for an approx 12x12x8" ABS enclosure with a thick rubber seal and stainless steel screws to hold the hinged door shut.
I used homebrew power over cat5 to simplify wiring. Make sure to run all wiring out of the bottom of the box and use a product called marine goop to seal it. Never had a moisture or connectivity problem the whole time. We are using 24dBi grid antennas to span a 3/4 mile gap.
I've been using a wet11 for my ps2 for a week with no problems. If you are using the default settings for your wireless network (no WEP, SSID of linksys) you shouldn't have to configure the wet11 at all. Good luck...
If you are using WAP11 APs already it is actually cheaper to buy another WAP11 and put it in "client access mode". That's what I did. The WET11s were going for $130 *IF* you could find one, but the WAP11s were going for $105 shipped from buy.com.
I just bought another WAP11 and put it behind my home theater, set up bridging mode, and plugged in a hub. Works great with my Rio Receiver, XBox, PS2, etc.... So, it was cheaper and can be used as a full AP later if needed.
Correct me if I'm wrong - something labelled as a "Network Bridge" should pass packets from one side of the bridge to the other unaltered, and simply keep a table of what addresses are on what side so as to pass packets when necessary between two broadcast segments.
Close. A network bridge does not separate broadcast segments, but passes all broadcast packets through to all available interfaces.
WET11 converts all MAC addresses on its "wired" network into it's own address. The reverse is different - it'll reassemble incoming wireless packets based on what I guess was their original IP source, and place the MAC address it replaced with its own back in the packet. Go figure why they go through all the trouble.
Hmm. I don't know much about 802.11 but Part 2 is easy; it is a result of part 1. If the WAP didn't put the real destination MAC address back in, the real destination will ignore the packet unless it is promiscuous mode.
The interesting question is why change the wired MAC addresses in the first place. I've loooked at the 802.11 header format, and it would appear the behavior you describe is standard. There is a "ToDS" flag bit, that if set means the packet is intended for an AP for forwarding. The standard then says that in this case the 802.11 destination address field should have the AP MAC address rather than the recipient.
I think this may have something to do with ad hoc vs. infrastructure mode. In ad hoc mode, each wireless station talks to each other wireless station. In infrastructure mode the packets always pass through the WAP. Each of these modes have their advantages. For infrastructure mode to work, every packet transmitted by a wireless node needs to have the WAP's link address. Cards should not try to handle packets, even if they can see it and are the ultimate destination, because in this mode they are supposed to wait for the WAP to retransmit it with their MAC address in the destination field.
Of course this issue is moot when we are talking about connecting wireless nodes to wired nodes, but the fact remains the WAP is going to ignore any wireless packets that aren't broadcasts or targetted to it's MAC.
The behavior which you desire might be accomplished by setting up an ad hoc network, and putting a box on it with bridging software which talks to both the wireless and wired network. I wonder if a Linux box could be configured this way, using the Linux kernal's bridging features. It might not work since the wireless network is somewhat different from the wired, but it would be worth looking into if there were a need to do some protocol other than IP (note that WAPS can't be protocol agnostic like bridges can be because they have to do a network address to MAC address translation).
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
We're talking two issues here: cheap and simple. I don't think the average consumer would spend $1,300 to get the wireless bridge + AP that the Cisco gear would cost, and I don't think the average consumer could figure out how to configure it!
The WET11 is pretty straightforward, just as hard as hooking up a client to an AP, and it's dirt cheap.
Freelance tech journalist for the Economist, MIT Technology Review, Macworld, and others
Actually, an AP bridges from wired to wireless. The WET11 can take a pod of up to 30 wired machines (or rather, machines attached to a single Ethernet segment) and bridge all of their traffic to ANOTHER access point. The WET11 is a wired-to-wireless bridge that hooks into a wireless-to-wired bridge.
Put 30 machines in a room on one side of the San Francisco Bay, plug in a WET11, point an antenna to an AP on the other side, and presto: you're running a large (very latent) Ethernet network.
Freelance tech journalist for the Economist, MIT Technology Review, Macworld, and others
What's missing from this explanation is consideration of the WAP11 which can also bridge a wired segment wirelessly to another wired segment via another WAP11.
The problem is that neither WAP11 can serve wireless clients at the same time. With one of these in place of one of the WAP11s, the WAP11 can both link individual wireless client machines AND bridge to the remote wired segment served by the WET11.
Re: "Broadcast segments" - You are absolutely correct sir. My mistake. I unfortuantely have a tendency to use the word "broadcast" when in reality I mean collision. Broadcasts should indeed be passed to all interfaces, and the WET11 handles this appropriately. What I originally meant was that I thought bridges were supposed to separate collision domains - packets would only be passed through the bridge if the destination address was on the other side.
:)
Re: behaviors: Indeed part 2 is a direct consequence of part 1. If you send packets out with a modified source MAC, the reply's destination will have to be that same modified MAC. However, I still fail to see why the WET11 needs to change MACs in the first place. D-Link has a device similar to the WET11 in function (sorry, don't know the name) that reportedly passes packets on transparently. From what I can tell, on my BEFW11S4 access point, the Wireless connector acts simply as a switched port. It keeps a table of attached MACs in order to minimize traffic effects.
Personally, I suspect Linksys is using the MAC translation in order to allow more devices behind WET11s to connect to a single Access Point. I mean, imagine your accesspoint has an address table of 5 MACs (just a sample number for my point). A single WET11 is designed to have up to 30 devices behind it, so passing each one's MAC address would overload the Access Point and make it not work. However, if a single MAC is passed for the whole network the Access Point would be able to handle up to 150 devices with 5 WET11s! NOTE: This is pure conjecture on my part.
I don't know if there's a difference between Infrastructure and Ad-Hoc modes. All I've worked with is Infrastructure, so I've no information on Ad-Hoc. However, Linksys has some documentation indicating that two WET11s, linked to each other in ad-hoc mode would allow XBoxes to communicate with each other, which might indicate no MAC changes in ad-hoc...
The way I see it, the WET11 should act as a pure bridge, and simply keep tabs on which MACs are on which side of the bridge and forward accordingly, and of course transparently. This would also allow the WET11 to forward protocols other than IP - one of the objectives you suggest...
I guess what I'm saying is if you're gonna build and market a Network Bridge, make it just a BRIDGE, dammit.
-Jack Ash
I used to work at a PDA dev shop that used 802.11a, and when people complain on various forums about the WAPs, the underlying problem isn't the WAP, it's the cards in your laptop/computer. Get ones based on the Orinoco, they may cost slightly more, but their range, performance, and speed were far superior to the, for example, Linksys PCMCIA cards.
Hey, I'm just your average shit and piss factory.
Yep, I'm using it with my PS2 and a BEFW11S4 ver 2 router. No problems so far, but it only arrived yesterday. I haven't had to set up any sort of port forwarding to get the setup working with SOCOM. The voice chat works fine.
A couple of minor notes. I haven't been able to properly set up WEP since none of my PS2 Linux browsers work very well with my routers setup page. I can't access the WET11's setup page at all.
Internet speed seems about as fast as a direct connection of my PS2 to my cable modem. However it takes longer to connect to IRC servers than before.
I bought the WET11 and my router with the express purpose of using them with my PS2.